move tests to unit test
enable delimited payload token filter

closes #3859
fix bug in term vector api, payloads were not handled correctly when some where missing

The array holding the payloads (TermVectorFields.payloads) is reused for each token. If the
previous token had payloads but the current token had not, then the payloads of the previous
token were returned, because the payloads of the previous token were never invalidated.
For example, for a field only contained two tokens each occurring once, the first having a
payload and the second not, then for the second token, the payload of the first was returned.

closes #3873
[DOCS] Add doc for delimited payload token filter
Add match query support for stacked tokens

SynonymFilters produces token streams with stacked tokens such that
conjunction queries need to be parsed in a special way such that the
stacked tokens are added as an innner disjuncition.

Closes #3881
[DOCS] Note that cutoff_frequency doesn't handle stacked tokens gracefully
Disable testSegmentsWithMergeFlag with AwaitsFix
index another doc in test and flush to force merge
Replaced hardcoded boolean value with correct parameter

Implemented changes suggested by review.

Closes #3898
fix naming in function_score

    - "boost" should be "boost_factor"
    - "mult" should be "multiply"

Also, store combine function names in ImmutableMap instead of iterating
over all possible names each time.

closes #3872 for master
Initial get field mapping setup
Added some tests
test passes
Added include_defaults option to getfieldmappings